/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.kie.api.runtime.process;

/**
 * An interface that represents an element that is listening
 * for specific types of events.
 */
public interface EventListener {

    /**
     * Signals that an event has occurred. The type parameter defines
     * which type of event and the event parameter can contain additional information
     * related to the event.
     *
     * @param type the type of event
     * @param event the data associated with this event
     */
    void signalEvent(String type,
                     Object event);

    /**
     * Returns the event types this event listener is interested in.
     * May return <code>null</code> if the event types are unknown.
     */
    String[] getEventTypes();

}
